Mercia Research review for UK buyers

Mercia publishes nine complete COAs from Janoshik Analytical, each paired with matching heavy-metals and endotoxin reports. All nine cover at least four test categories across identity, concentration, heavy metals and endotoxin. Seven also report purity, ranging from 96.470% to 99.959%. The short, single-batch history and material concentration and endotoxin findings limit the score. For these reasons, we rate Mercia Research 8/10 for COA practices.

Trustpilot shows 4.2/5 from 11 reviews on November 12, 2026, with ten five-star reviews and one one-star review. Buyers repeatedly describe quick delivery, helpful communication and careful packaging. The one-star review reports a wrong product and weeks spent seeking a resolution through WhatsApp. Mercia replied asking for the order reference and offering priority investigation. The independent record is small and more mixed than the unqualified customer claims on the storefront.

Companies House lists active Mercia Research Limited, company 17189709, incorporated on April 29, 2026. John-Paul Bartholomew Charles Kelly is its listed director. The registered office is 5th Floor, 167–169 Great Portland Street, London W1W 5PF, matching the website. The .com registry dates the domain to April 28, 2026. Mercia says orders ship from a UK fulfillment partner. The London address is a registered office.

UK shipping costs £15 and becomes free at £300. Orders placed Monday to Thursday usually dispatch the next business day by Royal Mail Tracked 24. Friday-to-Sunday orders dispatch from Monday. Typical UK transit is 1–2 business days after dispatch. The checkout offers credit/debit cards, Apple Pay and bank transfer by invoice. Its destination selector covers the UK and EU countries. Temperature-sensitive goods normally cannot be returned after dispatch. Damaged, wrong or defective deliveries should be reported within 48 hours.